U.S. Pat. No. 6,012,271 discloses a baler with a main drive 7 having two output shafts 8 and 9. The output shaft 8 drives the rollers 2 of the bale forming chamber via a main drive roller 12. The output shaft 9 drives the conveying rotor 4 and the pick-up member 3. A torque indicator 16 serves as a load sensor for the output shaft 8 for the rollers 2, 12. An overload clutch 17 secures the output shaft 9 for the feeding devices 4, 3. The torque indicator 16 is also connected with the overload clutch 17. In one embodiment the feeding units 4, 3 are switched off if a bale has to be wrapped.
The baler described in DE 102007031187 A1 distributes driving torque by means of a main gear box 11 onto the pick-up unit 7 comprising a pick-up rotor and onto a pressing chamber 6 surrounded by belts 5. The gear box 11 is driven by an input shaft 10. A first output shaft 12 drives a roller 4 for the pressing chamber 6 and has an overload clutch 16 and a fly wheel 17. A second output shaft 15 drives the pick-up unit 7. A sensor 25 measures a force which depends on the torque transmitted by the first output shaft 12. A clutch 23 is arranged between the main gear box 11 and the pick-up unit 7. A gear shift 30 between the gear box 11 and the first output shaft 12 can change the rotational speed of the belts 5 with respect to the pick-up unit 7, cf. [0029].
In EP 2250876 A1 a baler 14 pulled by a tractor 12 is disclosed. Several belts 36 surround a bale forming chamber of the baler 14, cf. FIG. 1. Crop material is picked-up and guided through a flow path 58 into the bale forming chamber. An automatic reaction how to handle a plug 16 is described. A “plug” may be a blockade, a restriction, or an overload situation, cf. [0020].
In case of such a plug 16 a controller 60 of the baler 14 of EP 2250876 A1 activates several actuators 44 to 56. In the embodiment this activation step causes the following steps, cf. [0013]: A baffle 30 is moved away from the material flow path 58. Knives 32 drop away from the flow path 58. A drop floor 34 moves away from the flow path 58. The tension of the pressing belts 36 is reduced. An example is given in par. [0018]: The available PTO drive power is diverted to areas where this power is most needed. In the example the driving tractor 112 yields no more than 150 HP at the PTO shaft. 50 HP is used for forming a bale and 100 HP is used for feeding crop material through a crop slug. If a plug 16 occurs in the crop slug, the tension of the belt 36 may be reduced such that only 20 HP is used for rotating the bale whereas 130 HP is used for feeding material through the feeder. The ability of the baler 14 is enhanced.